Absorption refrigeration



Patented May 19, 1936 UNITED STATES 2,040,895 ABSORPTION REFRIGERATION Glenn F. Zellhoefer, Bloomingtori, II].

No Drawing.

Application December 11, 1934, Serial No. 156,977

2 Claims. (01. 252-5) The present invention relates generally'to a solvent material and a refrigerant mixture for absorption refrigerating machines, both of the two-fluid type and of the three-fluid type.

In absorption refrigeration there is required a solvent material adapted to remain liquid throughout the operation of the apparatus, and a refrigerant material adapted to have a liquid and a vapor phase in the cycles of operation, adapted to be dissolved or absorbed in the solvent, adapted to be evaporated or boiled as a vapor from the solvent mixture and from the solvent, and adapted to be condensed from the vapor to a liquid. Numerous refrigerants and numerous solvents are known, as well as successful combinations thereof with refrigerants.

A particular object of the invention is the use of diethylene glycol monoethyl ether acetate as a solvent.

' Another object is the use of a combination of' said solvent with the refrigerant dichloromonofluoromethane.

Examples of the two-fluid apparatus in which the new, solvent material and the new combination may be used is disclosed in my co-pending application Serial No. 651,306, filed January 12, 1933, or in my U. S. Patent No. 1,895,698, issued January 31, 1933. Other examples may readily be cited, and will be known to those skilled in the art.

The two-fluid apparatus above referred to, briefly described, comprises a still in which a liquid mixture of solventand refrigerant is heated to distill away as a vapor the refrigerant material, a condenser wherein said vapor is condensed to a liquid state, an evaporator wherein the resulting liquid is vaporized at reduced pres- I sure to produce refrigeration, and an absorber in a which vapor of the refrigerant material containv is directed to a new sol-' vent for absorption refrigeration, and to combimeans are included, and automatic controls may. be provided.

The particular characteristics of such a machine are that the still operates at temperatures well above normal temperatures, such 'for example at 210 F. to 250 F.; and that the cooling unit operates at temperatures lower than normal, such asfrom 15 F. to 50 F. Various parts of the apparatus differ in the prevailing temperatures and pressures, and both pressure and temperature determine the physical state of the free refrigerant, such as odor, viscosity, heat capacity,

boiling point, freezing point, volatility, chemical stability, reactivity, corrosive action, inflammability, toxicity, etc.

By considering the limitations herein set forth and suggested, I have been able to utilize diethylene glycol monoethyl ether acetate as a solvent, for practical usage, in combination with the refrigerant, dichloromonofiuoromethane, which is little known.

.The new solvent is herein named as diethylene glycol monoethyl ether acetate, but it may be characterized by others as carbitol acetate. However, in order to leave no doubt as to,its identity, its structural formula is herein given:

CzHsOCHzCHzOCH-zCHzOCOCI-Ia The refrigerant herein specified is dichloromonofiuoromethane. However, in order to leave no doubt as to its identity, its structural formula is herein given:

, CHClzF In the accompanying claims the invention is set forth as a combination useful in absorption refrigeration. It is to be understood that a simple adulteration of the'new solvent in its pure form, either by reason of commercial impurities, or by addition of lesser quantities of other ma'- terial, useful also as solvent, is permitted, and such a composition is intended to fall within the scope of the present invention.

The solvent herein specifically claimed is covered generically in applicant's later application Serial No. 17,064, illed April 18, 1935.

What I claim is r 1. A, refrigerant mixture for the absorption type of refrigeration apparatus consisting of diethylene glycol monoethyl. ether acetate as the essentially predominant solvent, and diehlor'omonofluoromethane as a refrigerant.

2. A refrigerant mixture for the absorption type oi'retrigeration apparatus consisting of dietlLvlene glycol monoethyl ether acetate as the essentially predominant solvent, and a volatile chemically stable halogenated hydrocarbon re- 5 i'rigerant soluble in said solvent.

GLENN r. zmmom. 

